1. Stannous fluoride protects against erosion
Two separate investigations assessed the ability of two fluoride dentifrices to protect against the initiation and progression of dental erosion; a predictive in vitro erosion cycling model and a human in situ erosion prevention clinical trial. A stabilised stannous fluoride (SnF2) dentifrice (0.454 % SnF2 + 0.077 % sodium fluoride [NaF]; total F = 1,450 ppm F) [dentifrice A] and a sodium monofluorophosphate [SMFP]/arginine dentifrice (1.1 % SMFP + 1.5 % arginine; total F = 1,450 ppm F) [dentifrice B] were tested in a 5-day in vitro erosion cycling model and a 10-day randomised, controlled, double-blind, four-period crossover in situ clinical trial. In each study, human enamel specimens were exposed to repetitive treatments followed by erosive acid challenges. Both studies demonstrated statistically significant differences between the two dentifrices, A providing significantly better enamel protection. In vitro, dentifrice A provided a 75.8 % benefit over dentifrice B, while in the in situ model, A provided 93.9 % greater protection. This support the superiority of stabilised SnF2 dentifrices for protecting human teeth against the initiation and progression of dental erosion.

West NX et al. Erosion protection benefits of stabilized SnF2 dentifrice versus an arginine–sodium monofluorophosphate dentifrice: results from in vitro and in situ clinical studies. Clin Oral Investig 2017 21: 533-540.

Q For these investigations into protecting human teeth against the initiation and progression of dental erosion, which of the following is true of the findings?
A Only the in situ trial found stabilised SnF2 dentifrices to be superior
B Only the in vitro model found the SMFP]/arginine dentifrice to be better
C Both investigations support the superiority of stabilised SnF2 dentifrices
D Neither dentifrice had the desired protective effect

  1. To floss or not to floss?
Does flossing help with periodontitis? A vexed modern question was hoped to be given an answer by a cross-sectional study using data from the National Health and Nutrition Examination Survey years 2011-2014. Three categories of flossing: 0-1, 2-4 and >=5 days in the past week and the CDC definition of periodontitis were used, and odds ratios were calculated controlling for age, gender, smoking, drinking, income and dentist visits. A total of 6,939 adult subjects were included, 35% flossed <=1 time a week, and 40% had periodontitis. After adjustment, the odds of periodontitis were 17% lower for subjects who flossed >1 time a week than for subjects who flossed less often. Younger subjects, non-smokers and subjects with the highest incomes had lower odds of having periodontitis. Flossing was associated with a modestly lower prevalence of periodontitis. Older age, being male, smoking, low income and less frequent dental visits were associated with a higher prevalence of periodontitis. Flossing 2-4 days a week could be as beneficial as flossing more frequently.

Cepeda MS et al. Association of flossing/inter-dental cleaning and periodontitis in adults. J Clin Periodontol 2017 Jun 23.

Q Which patients are likely to have a lower prevalence of periodontal disease?
A Younger males who do not floss
B Younger women who floss >1 time a week
C Older male smokers who floss >1 time a week
D Those with low incomes and less frequent dental visits

  1. Unvarnished results of fluoride varnish
A randomised controlled trial of 275, two- to three-year-old children without cavitated carious lesions from 28 nonfluoridated rural preschools assessed the effectiveness of biannual fluoride varnish applications to prevent early childhood caries. An oral health education component was administered to children, parents and educators. A new toothbrush and toothpaste for each child was delivered to the parents at baseline and at four follow-up visits. The participants were randomly allocated to receive fluoride varnish or placebo applications every six months with 131 participants in the intervention group and 144 participants in the placebo group; of these children, 89 (67.9%) 100 (69.4%) completed the protocol respectively. Trained, calibrated dentists blind to the groups performed visual dental assessments at 6, 12, 18 and 24 months. Caries incidence was 45.0% for the experimental group and 55.6% for the control group with a mean dmft of 1.6 and 2.1 respectively. No adverse effects were reported. The authors concluded that biannual fluoride varnish application was not effective in preschool children from rural nonfluoridated communities at a high risk of caries.

Munoz-Millan P et al. Effectiveness of fluoride varnish in preventing early childhood caries in rural areas without access to fluoridated drinking water: A randomized control trial.
Community Dent Oral Epidemiol 2017 Aug 29.

Q Which of the following preventive measures was effective against caries in this research?
A An oral health education component
B Application of fluoride varnish
C A new toothbrush and toothpaste for each child
D None of the above

  1. Chew this over
The caries preventive effect of 1 year use of low-dosage xylitol chewing gum in a high-caries-risk adult population was evaluated by assigning 179 high-caries-risk adults to two experimental groups, xylitol and polyols. Caries status, salivary mutans streptococci (MS), and plaque pH were re-evaluated after 2 years from baseline in 66 xylitol and 64 polyol subjects and the net caries increment for initial, moderate, and extensive caries lesions and for the caries experience were calculated. For the xylitol group it was 1.25 +/- 1.26 and for the polyol group 1.80 +/- 2.33. Subjects treated with xylitol chewing gums had a reduction of risk rate at tooth level of 23% with respect to those treated with polyols. The area under the curve at pH 5.7 was statistically significantly lower during the experimental period in the xylitol group as was a decrease of the concentration of salivary MS. Subjects using the low-dose xylitol chewing gum showed a significantly lower increment of initial and extensive caries lesions and overall a lower increment of caries experience.

Cocco F et al.  The caries preventive effect of 1-year use of low-dose xylitol chewing gum. A randomized placebo-controlled clinical trial in high-caries-risk adults. Clin Oral Investig 2017 Mar 16.

Q Which of the following was caused by use of a xylitol chewing gum?
A A rise in the area under the pH curve
B Caries risk rate rise
C A fall in extensive caries lesions
D A rise in salivary mutans streptococci